#!/bin/bash 
ETH=$1 
while : ; do 
  time=`date +%m"-"%d" "%k":"%M` 
  day=`date +%m"-"%d` 
  rx_before=`ifconfig $ETH|sed -n "8"p|awk '{print $2}'|cut -c7-` 
  tx_before=`ifconfig $ETH|sed -n "8"p|awk '{print $6}'|cut -c7-` 
  sleep 2 
  rx_after=`ifconfig $ETH|sed -n "8"p|awk '{print $2}'|cut -c7-` 
  tx_after=`ifconfig $ETH|sed -n "8"p|awk '{print $6}'|cut -c7-` 
  rx_result=$[(rx_after-rx_before)/256] 
  tx_result=$[(tx_after-tx_before)/256] 
  echo "$time Now_In_Speed: "$rx_result"kbps Now_Out_Speed: "$tx_result"kbps" 
  sleep 2 
done
